The present invention relates to the field of printing materials and, more particularly, to a an imaging member having an array of closely packed cup-shaped features thereon and a print substrate onto which the imaging member is adapted to be selectively transferred to print information thereon. Disclosed herein are ultra-violet (UV) curable gellant inks for ink jet printing on a substrate in Braille, raised print, regular print, or a combination thereof. Also described is a method for forming images comprising Braille, raised print, regular print, or a combination thereof with the described UV curable gellant inks.
There are two main technologies available for printing Braille and raised characters: embossing and thermal paper expansion. These devices produce lines made from dots which provide poor image resolution and are unable to print variable height graphs and images. When required, variable height such as graphs are typically fabricated by hand using a thermoforming process. Further, embossers are extremely noisy machines, requiring acoustic cabinets. Thermal expansion paper is also very expensive, typically over a dollar per sheet, requires a complicated and slow two-step printing process, and is limited to specialty plastic-like substrates.
Yet another technology that has been used for printing Braille and raised characters is ink jet printing, which generally employs inks that are solid at room temperature and liquid at elevated temperatures. Such inks may be referred to as solid inks, hot melt inks, phase change inks and the like. While conventional solid ink technology is generally successful in producing vivid images and providing economy of jet use and substrate latitude on different substrates, such technology often does not meet the additional requirements for specialized applications such as Braille and raised print applications. Specifically, solid ink lacks the durability and robustness for a Braille application, and can easily be flaked or rubbed off with repeated contact and rubbing.
As such, there is a need to overcome the deficiencies of conventional printing technology for printing Braille and raised characters to better serve the market. Advantages of digitally producing Braille and raised text are personalization, accessibility to home users, ease of combination with regular text, and the ability to easily generate Braille representations of mathematical and chemical equations and financial formulae. There is a need in the art for a Braille printing process that include rounded dots, a transfuse architecture that is compatible with current solid ink technology, and elimination of teardrop or elongated dots that could possibly be formed in a current direct to paper moving path architecture.